2022/12/09 (Friday)
- Lab in-personnel: Zach, Himangshu, Matt
| Status | Run 76 ending |
|---|---|
| Setup | Cables 2/3/1 → diverter/nothing/nothing → Side1-readout HV CONN 1/3/2 → HV 1(L)/2(R) → DCRC55(1)/DCRC50(3), DCRC33(2)→HV control, NaI trigger signal → DCRCX(4) Lead/poly shield fully assembled. Boron-filled socks covering NaI detectors. PuBe removed from lab. NaI trigger window to 4.73-5.13 MeV |
| Warming up. Mixture recovered to dump yesterday. Mixture removed from LN2 Trap 1 but it still has contaminants. | |
| 1155 | MC(Cernox)/Sorb = 13.0/42 K |
| 1240 | Perform 13K electrical checks on all 3 cables at breakout box. Findings: |
- Cable2 SQUID_A reads open
- Cable1 SQUID_C and SQUID_D read open
- Cable3 SQUID_C and Feedback_C read open
- (these are all Side1 channels)
- (this makes sense with the Side1 phonon checks 2 days ago, 4 channels could not be unrailed)
- specifically: HV2pB/HV2pC/HV1pA/HV2pA=Cable3pC/Cable1pC/Cable2pA/Cable1pA, all railed in pulse viewer, all show electrical checkout problems (open SQUIDs)
- HV1pB/HV1pC=Cable2pB/Cable2pC are OK
| 1250 | Quick leak checker test on IVC: 2400 pbarL/s, lower than yesterday. Quick He squirts at stripline elbow and other connections around ebox, no increase in signal. |
|---|---|
| 1300 | Check contents of LHe trap. We've had it isolated overnight after removing mixture yesterday. Now Sorb is at 43 K, LHe trap is probably at similar temperature. First pump out G1 volume with Scroll pump. Close V2, open V1. LHe trap = 176.8 mbar, pretty high. Pump out with Scroll pump. |
| 1310 | LD on IVC: 4130 pbarL/s. Has been creeping up over the last 20 minutes. |
| 1315 | Use Scroll pump to pump out fridge. It was already pretty low. |
| 1315 | LD on IVC: 4140 pbarL/s. |
| 1315 | Let mixture into both sides of the fridge through V14, V3 and V1 (and Condenser speedi and Still gate valves). No increase seen in LD signal. |
| 1320 | Start pumping mixture back to dump. Increase V6 to 30% after P1 falls into range. |
| 1325 | Turbo on IVC = 86 nbar. With Turbo valved out for a few minutes, IVC = 630 nbar |
| 1515 | Finish pumping mixture to dump, close all IVC valves, turn off 3He pump. |
| 1515 | MC(Cernox)/Sorb = 16.2/47.4 K |
| 1518 | Recovery = 700895.49 cuft (@ 15:18:32), 8.8 cuft/hr |
| 1540 | Let 3.4 mbar He gas into vacuum manifold. Then open cryostat vacuum jacket valve to let this into the vacuum jacket. Vacuum Jacket → 0.10 mbar. |
| 1544 | Recovery = 700909.66 cuft (@ 15:44:43), 152 cuft/hr |
| 1550 | Let He gas into IVC. Two tube-lengths of He gas (tube from wall to pump manifold). IVC → 0.34 mbar. MC temperature rises quickly, 16.6→19.2 K in five minutes. |
| 1605 | Recovery = 700933.25 cuft (@ 16:05:56), 16.3 cuft/hr, much lower. Looks like we've pretty much boiled off the last puddle of LHe. |